When designing the rectifier circuit, selecting the power diode should consider the following:
1. The forward pressure reduction should be small to reduce the loss, improve efficiency;
2. Reverse recovery current peak (i
RM) Small, reverse recovery time T
RR should be small, especially the diode is more important when the Di / DT is directly reversed from the forward conduction state;
3. Positive recovery voltage V
RFM is small, especially with high-speed tubes high with PIV (reverse peak), and use ultra-fast recovery diode;
4. Reverse leakage current I
R small, especially in the case of high voltage and high testing.
concept:
1. Fast Recovery DioDe
The PN nut flow tube that is quickly transitioned to the shutdown state is called a fast recovery diode (FRD). Features is short in reverse recovery time.
2. Schottky diode (SBD, SCHOTTKY BARRIER DIODE)
The ordinary diode utilizes the unidirectional conductivity of the PN junction, the Schottky diode uses the barrier rectification of the metal and semiconductor surface, referred to as "metal semiconductor junction"; its full name - Schott Base Base diode. Due to the increasing cumulative, there is no positive or reverse recovery phenomenon, T
RR is very small. Disadvantages: The reverse leakage current is much larger than the ordinary diode!
